We present a novel setup of a quark-antiquark antenna splitting inside a color deconfined medium considering the finite formation time of the dipole, which becomes an important scale in the physical picture. In particular, we consider the splitting of a color singlet dipole, studying in detail its formation and subsequent propagation through the medium. We discuss the role of color coherence and the relevant time scales which control the scenario, while also providing theoretical support for vacuum-like emissions early in the medium. Finally, by mapping the spectrum of in-medium splittings through the corresponding kinematical Lund diagram, we elicit regimes of a close correspondence to a semi-classical description and regimes where this description breaks down.